1. Field of the Invention
The present invention relates to a connector into which memory cards, such as micro-SD cards, SIM-cards and micro-SIM cards, are removably insertable, and in particular, relates to a memory card connector into which two memory cards are removably insertable.
2. Description of Related Art
This type of memory card connector known in the art is disclosed in, e.g., Japanese Unexamined Patent Publication 2003-323943.
The memory card connector disclosed in the above-mentioned publication is constructed of a first connector and a second connector which are superposed on each other in the direction of thickness thereof.
The first connector has a first housing and a first group of contacts. The first housing is rectangular in overall shape and has a first storage slot (storage section) into which a first memory card is removably insertable, and the first group of contacts are electrically connected with terminals of the first memory cards inserted into the first storage slot. On the other hand, the second connector has a second housing and a second group of contacts. The second housing is identical in overall shape to the first housing and has a second storage slot (storage section) into which a second memory card is removably insertable, and the second group of contacts are electrically connected with terminals of the second memory cards inserted into the second storage slot.
Each contact of the first group of contacts of the first connector has a first tail which is mountable to a circuit board and positioned on the outer peripheral side of a first side surface serving as one side of the first housing, as viewed in the direction of thickness of the first and second connectors. In addition, the second housing has a first side surface (parallel to the aforementioned first side surface of the first housing) that is positioned on the same side as the first side surface of the first housing, and the second group of contacts of the second connector has a second tail which is mountable to the aforementioned circuit board and positioned on the outer peripheral side of the first side surface of the second housing as viewed in the aforementioned direction of thickness of the first and second connectors.
Some of the first tails of the first group of contacts of the first connector and some of the second tails of the second group of contacts of the second connector are alternately arranged (along the longitudinal direction of the first side surfaces of the first housing and the second housing).
The first connector and the second connector are mountable to a circuit board. More specifically, with a circuit board, the first connector and the second connector being superposed in that order, the first connector and the second connector can be mounted to the circuit board by soldering the first tails, which are formed at ends of the first group of contacts, and the second tails, which are formed at ends of the second tails of the second group of contacts, to the circuit board.
Since some of the first tails of the first group of contacts of the first connector and some of the second tails of the second group of contacts of the second connector are alternately arranged, the distance between any two adjacent first and second tails (i.e., the pitch of the alternately-arranged first and second tails) is extremely small. Therefore, the mountability of the first tails and the second tails to a circuit board easily deteriorates. In other words, positions (images) of the first and second tails are difficult to recognize by an image recognizer, and accordingly, defective soldering easily occurs between each of the first and second tails and the circuit board.
In addition, since the first tails (first contacts) of the first connector and the second tails (second contacts) of the second connector which are alternately arranged are mutually different in shape, it is difficult to make an alignment adjustment for the first tails and the second tails with respect to the circuit board (i.e., to make an adjustment to make the first tails and the second tails lie in a plane). In other words, a difference (difference in level) easily occurs between the distance (clearance) (in the direction of thickness of the circuit board) between the first tails and the circuit board and the distance (clearance) (in the direction of thickness of the circuit board) between the second tails and the circuit board. If such a difference occurs, the tails (the first tails or the second tails) of one of the first connector and the second connector come in contact with the circuit board, whereas the tails (the first tails or the second tails) of the other connector are inevitably spaced from the circuit board, so that there is a possibility of defective soldering occurring between the tails of the aforementioned other connector and the circuit board when the spaced distance (separated distance) therebetween is great.
Additionally, in the case where the memory card connector (a memory card) is small in size, if it is attempted to arrange the first tails and the second tails alternately, the distance between any two adjacent first and second tails (i.e., the pitch of the alternately-arranged first and second tails) would be extremely small, which makes it difficult to mount the first tails and the second tails onto the circuit board. Consequently, it is difficult to apply the technical idea disclosed in the aforementioned Japanese Unexamined Patent Publication 2003-323943 to a small-sized memory card connector.
Additionally, in order to alternately arrange some of the first tails of the first group of contacts of the first connector and some of the second tails of the second group of contacts of the second connector, it is sometimes the case that either the first tails or the second tails are each required to be formed into a complicated shape (e.g., a crank shape), which easily causes the production cost thereof to increase.